'Those expecting a "fashionista" festival will feel justifiably disappointed,' writes couturier Christian Lacroix, guest curator of this year's Arles photography festival, in his catalogue essay. Well, yes and no. While resisting the urge to turn the festival into a total celebration of fashion photography, Lacroix has nonetheless elevated that most staged, and often superficial, genre by placing the work of Paolo Riversi, Peter Lindbergh, Gregoire Alexandre and the late Richard Avedon at the heart of this big, sprawling and, it has to be said, uneven, event. Any fashionistas passing through Arles between now and September are in for a treat. Photography fans may have to dig deeper for their pleasures.

The two fashion-based exhibitions I enjoyed most are worlds apart. The first features Tim Walker's elaborate fairy-tale tableaux which merge high fashion and high concept to surreal effect. Everything here is otherworldly, from the knitted cars to the giant accessories, and he invests the images with a definably English sense of whimsical humour that is often missing from this kind of staged photography. A few streets away, in the Espace Van Gogh, are two walls of Sabine Weiss's images from the 1950s of window displays at the Printemps department store in Paris. Mannequins stare blankly from beneath polka-dotted parasols, or sit mute beneath baroque chandeliers. This is fashion as public spectacle, tantalisingly out of reach of most passers-by.

In the same space, Olivier Saillard, who curates fashion exhibitions at the wonderful Musée des Arts Decoratifs in Paris, has put together a show of copyright registration photographs, basically black-and-white images of designs made by the greats of French fashion, the likes of Madame Vionnet, Paul Poiret and Elsa Schiaparelli. It's a simple, enchanting show that highlights the art of fashion by concentrating on the designs themselves rather than the image-makers. The V&A should snap it up.

Elsewhere, this year's Rencontres was a mixed bag that never quite lived up to its promise. Tuesday night's projection in the epic setting of the Roman amphitheatre was devoted to the work of Françoise Hugier, now a French national treasure. Spanning several decades and styles, from reportage to fashion, it would have benefited from better editing and, as is often the case here, it was accompanied by a musical soundtrack that seemed designed to lend gravitas to images already laden with meaning and metaphor. I never want to see another representation of the 'otherness' of Africa or 'exoticness' of Asia as long as I live.

That same evening, Jacob Aue Sobol, whose book Sabine I championed in these pages a few years back, won a Leica award for his grainy reportage from Japan, although to me the images seemed a little too redolent of the work of Anders Pedersen, one of his inspirations. On the edge of town, in the vast spaces known as the Parcs des Ateliers, Lacroix's selections were more to my liking. Pierre Gonnord's giant portraits of people who live 'on the fringes of the established order' in Madrid were both powerful and tender, and brought to mind the work of Caravaggio in their composition and lighting. These faces stayed in my head for hours afterwards.

Likewise, but for different reasons, the portraits of South African Pieter Hugo, whose series The Hyena and Other Men is by turns startling and disturbing. Hugo spent months with a group of itinerant wild animal trainers, their children, hyenas and monkeys, in an urban settlement beneath a motorway in Lagos. The results redefine reportage and, when the initial shock of these often communal portraits subsides, will make you ponder questions of anthropology, society, belonging and family. This is powerful and, even on repeated viewing, unsettling work.

Also in the 'Discovery' section, I was much taken with the work of New Yorker Ethan Levitas and Londoner Nigel Shafran who both present understated images that possess a quiet cumulative power. Shafran's subject is his wife and son, and their domestic routine, but underlying that is a quest for the sense of order that holds at bay the creeping chaos of the everyday. This is difficult, elusive territory but Shafran, who walked away from a budding career as a style photographer, tackles it with a concentration evident in these intriguing images, the best of which capture the moments of quiet reverie we all experience without our even noticing them.

Ethan Levitas is a formalist at heart, and a master of muted colour. His images of New York subway trains crossing from Brooklyn to Manhattan are taken from the vantage point of nearby rooftops, ladders and fire escapes. The more you look at them, the more you see and, more often than not, what you are seeing is the same moment of private reverie. As with Walker Evans's surreptitiously taken subway shots, the subjects often seem to be staring straight into the camera, as if responding unconsciously to its presence. One man stands nonchalantly between two carriages, smoking and reading a magazine; another, white-bearded and biblical-looking, places his palm against the carriage window as if in acknowledgment of Levitas's lens. Beside him, a figure wreathed in a headscarf looks like a life-size rag doll. The seasons change with their usual New York ferocity, but the burnished rust on the chrome of the carriages is a constant. On one carriage window, the word MAD is scratched; on another the word MALICE. I began wondering what a Martian visitor would make of these frozen moments and their cryptic signs.

What, too, would an alien being make of Marla Rutherford's oddly light-hearted portraits of American fetish actresses, encased in latex corsets, face masks, stockings? Or Angela Strassheim's strangely morbid photographs of her born-again Christian family, which have been stylised to look like crime scenes? Or, indeed, Patrick Swirc's extended projection which takes the form of a plaintive-going-on-crazed, extended love letter to his recently departed girlfriend in the form of a daily photograph and accompanying spoken passage? Entitled Letter to Claire, it is a diary of undiluted heartbreak and suffering which, once you surrender to the embarrassment it provokes and feeds off, becomes a thing of raw and turbulent beauty. How Claire felt about it is not recorded. Then again, this is essentially about him, not her. By the end, though, you can kind of see why she left.

Two contrasting moments summed up Arles for me this year. Thursday night's staged face-off between Paolo Riversi and Peter Lindbergh was a big production number, as befits two of the giants of contemporary fashion photography. The two men sparred good-naturedly before an adoring audience while huge projected images of their work appeared behind them: basically images of unbelievably beautiful girls in unbelievably expensive clothes, or in no clothes at all. I kept thinking of Vanessa Winship's show, Sweet Nothings: The Schoolgirls from the Borderlands of Eastern Anatolia. The subjects stand uncertain and awkward before the camera, unsmiling and grave, their beauty as austere as their uniforms and the landscape around them. The great Czech photographer Josef Koudelka was honoured at Arles last night, and you sensed his spirit hovering over Winship's poetic reportage. The world of high-fashion photography seemed even more unreal and emptily beautiful than usual.